What route the Midland Highway would have taken between Mansfield and Morwell has been quite a mystery since the beginnings of the Aussie Highways. I recently found this article written by the Secretary of the Country Roads Board from 1938 which may shed some
light on the intended route for the 'missing link':
(k) Midland Highway from (i) Geelong to Ballarat via Meredith and Buninyong (ii) Shepperton to Benalla (iii) Benalla to Mansfield (iv) Morwell via Boolarra to Port Welshpool.
The Board contemplates the linking up of the 3 sections of the Midland Highway in order to provide a highway encircling the central portion of the State which will connect the highways radiating from Melbourne and have its terminus at either end at the deep
water ports of Geelong and Port Welshpool respectively. The sections contemplated are those from Ballarat via Avoca, Maryborough and Castlemaine, joining the Calder Highway which runs to Bendigo; from Goornong north of Bendigo, via Colbinabbin, Rushworth,
and Tatura to Shepparton; Mansfield via Woods Point and Walhalla to the Prices Highway East at Moe.